This invention relates in general to the field of video conferencing, and more particularly an automatic voice tracking camera system and method of operation.
In conventional video conferencing systems, infrared technology has been employed to track the position of a speaker in the video conference. This conventional method uses an IR transmitter and three IR receivers to triangulate the position of the IR transmitter which is carried by the speaker. This type of system may not work well in a conference room environment where a number of persons may talk at any given time.
A second conventional method for tracking a speaker is the use of touch-to-talk microphones. The position of each microphone is preset in order to direct a camera when a speaker touches a microphone to talk. The positions of the microphones are preloaded in the system so that the system knows where each speaker is to be located. This may be undesirable because it requires fixed positions of speakers, limits the movement of speakers, and is not easily portable.
Microphone array technology is being introduced in the video conferencing field in order to improve the reception of a sound and to allow location of the position of the source of the sound. This microphone array technology can be used in both conference room and classroom environments. The position information from such a microphone array is problematic if used to direct a camera because the position information changes continuously due to the movement of speakers and due to errors in locating the position of the speakers.
It is desirable in a video conferencing environment to provide automatic voice tracking of a speaker in order to control cameras such that there is natural camera movement in viewing a given speaker.
In accordance with the present invention, an automatic voice tracking camera system and method of operation are provided that substantially eliminate or reduce disadvantages and problems associated with previously developed video conferencing systems.
According to one aspect of the present invention, an automatic voice tracking camera system includes a first camera and a camera controller. The first camera is operable to receive control signals for controlling a view of the first camera. The camera controller is operable to determine a responsive camera movement of the first camera based upon coordinates for a point in space where the determination comprises comparing the coordinates with a first spacial region defined around a current speaker position. The camera controller is then operable to generate camera control signals based upon the appropriate responsive camera movement and to provide the camera control signals to the first camera. In one embodiment, the camera controller is further operable also to compare the coordinates with a second spacial region defined around the current speaker position.
According to another aspect of the present invention, a method is provided for automatically controlling a camera. The method includes determining an appropriate responsive camera movement from coordinates for a point in space where the coordinates are compared with a first spacial region defined around a current speaker position. Camera control signals are then generated based upon the appropriate responsive camera movement, and the camera control signals are provided to a first camera.
A technical advantage of the present invention is the automation of tracking a speaker in a video conference such that the camera views the speaker using only the voice of the speaker to determine the speaker""s position.
Another technical advantage of the present invention is the use of two cameras whereby a non-active camera can be used to find and view a new speaker prior to switching between the two cameras. In this manner, a switch to a new speaker does not include a scan between the two speakers.
A further technical advantage of the present invention is the movement of a camera to a new view only if the speaker""s position moves outside of a defined window. Thus, a minor position change is not translated into movement of the camera.
An additional technical advantage of the present invention is the use of a second defined window to determine whether a current camera or other camera should be used to view the speaker when the speaker""s position moves outside of the first defined window.
Another technical advantage of the present invention is the filtering of speaker position information to delay movement of the camera until a new position is verified. In this manner, insignificant noises that might otherwise result in a camera movement are filtered.
A further technical advantage of the present invention is the use of zoning of a conference room. A conference room is divided into a number of zones each associated with one camera. Each camera is then controlled to view speakers within its associated zone.